1. Field of the Invention
The present invention relates to a sensible body vibrator which produces special effects on the mind and body of a person resting on a body support, such as a chair or a bed, by imparting specific mechanical vibrations to the support.
2. Description of the Prior Art
Music is generally heard by the use of speakers or headphones apart from cases where live performances are heard. The sound from speakers has recently come to be reproduced over the entire audible range of the human ear, but the low-pitched sound of palpable intensity cannot be sensed by the body unless an extraordinarily loud sound is produced. One reason why music from speakers heard at homes or the like is lacking in moving the listener's heart in contrast to music heard at a concert hall or the like, is that the music heard at a concert hall or the like is heard with the sense of hearing and, at the same time, the low-pitched sounds of palpable intensity are sensed by the human body as well. This feature is lacking in the music heard at homes or the like.
Accordingly, for the purpose of correcting this inadequacy, apparatus have been devised by the present inventor and applications for patents therefor filed by the present assignee. These apparatus are typically arranged as follows: A vibration unit is provided for producing mechanical vibrations by supplying thereto an electric current of a low-frequency range below 150 Hz or thereabouts among the frequencies of sounds reproduced from a loudspeaker. This vibration unit is mounted on a body support such as a bed mat, a floor, or the like, and at the same time as music is heard from the loudspeaker, vibrations from the body support are received by the body, thereby producing the effect that the listener can listen to music just as if he or she is doing so at a concert hall.
For instance, Japanese Utility Model publication No. Hei 2-8467 discloses a vibration mat in which a vibration unit, which is supplied with a low frequency electric power, is imbedded and used by putting it on a bed. Japanese Utility Model laid-open application No. Sho 63-5788 discloses a bed mat in which a plurality of vibration units are disposed so as to make those located at every effective spot of the human body when a person lies on the mat. Japanese Utility Model laid-open application No. Sho 63-64194 discloses a vibration unit which is supplied with a low frequency electric power and fastened to the side of a bed mat.
As a vibration unit, various types are conceivable such as a solenoid type, a speaker type, or a motor type. A mechanism of the so-called speaker type is adopted for obtaining vibrations capable of coping with changing signals of music and suited to the compass and stress of music. In this mechanism, vibrations are obtained through magnetic interference action occurring when a magnet and a coil wound in the vicinity of the magnet are energized. In accordance with the vibration unit of this structure, quick changes of music signals can be accommodated unlike vibration units of other types.
Accordingly, it is possible to obtain vibrations that are optimally suited to the aforementioned usage. Furthermore, it is possible to cause the body support to vibrate by means of signals set to such waveforms and strength that are suited to the user's preference or that are medically or psychiatrically preferable.
Thus, since it has been verified that the apparatus of this type, in which vibrations are generated through the magnetic interference action of the magnet and the coil, are not only useful for appreciation of music but are medically or psychiatrically beneficial, these apparatus have become rapidly widespread.
The human ear, which is an acoustic organ, perceives sound waves, but it has long been pointed out that sounds are perceived not only by ears but by the entire body. In the low-frequency range in the audible spectrum of the human ear, the lower the frequencies, the greater the ratio at which the sound is sensed by the body than the case where it is heard by the ears. Acoustic energy in this low-frequency range has a characteristic that it causes a surface or an object against which it has collided to vibrate. This acoustic energy is not only sensed by the human body as sound pressure transmitted through the air, but also there are cases where the acoustic energy accompanies vibrations that are transmitted through the ground, a floor, or the like. These types of vibrations constitute elements of sound information, and are ultimately perceived as a sound.
Those vibrations that are sensed by the body when the sound pressure is transmitted through the air and causes the body to vibrate as well as those vibrations that are sensed by the body when the sound pressure is transmitted thereto through a floor surface or the like (regardless of whether they are sensed consciously or unconsciously) will be referred to herein as the "bodily sensible sound vibrations".
As for these bodily sensible sound vibrations, in general, the lower the frequencies, a greater proportion of them are sensed by the body more than by the ears. These bodily sensible vibrations bring about psychological and physiological pleasures, including the sense of low-pitched sound of palpable intensity, rhythmical sense, sense of energy, fascination, and ecstasy, thus appealing to human organic functions. On the other hand, certain types of vibration (sound) can arouse the senses of anxiety, tension, or a sensation of fear.
As an apparatus making use of bodily sensible sound vibrations, transducers (board speakers) of a sound reproduction system, which directly cause vibratory plate surfaces such as walls, ceilings, and floor surfaces to vibrate, were manufactured in the 1960s and 1970s.
Various types of transducers have also been developed by the present inventor for various purposes, and in an electrical system for driving them, audio signals are not only applied, but various types of signal processing techniques are employed. In that case, signal processing techniques are used that are adapted to the performance of both the transducer and a vibration system, and are suited to psychological and physiological conditions concerning bodily sensible sound vibrations. As various signal sources, apart from music, bodily sensible vibrations caused by the repetition of monotonous sounds, including documentary sounds such as those of running trains and steam locomotives, soothing sounds of waves or bells, are often used as part of music therapy. It is thus possible to obtain the effect that even if music is absent, both the mind and body can be relaxed by the bodily sensible vibrations using vibration signals alone.
As described above, the sensible body vibrator has the characteristic of serving as an auxiliary tool for audio equipment. Since it has been verified that this type of apparatus is medically and psychiatrically efficacious, the users are not confined to young people who are fond of music, and these sensible body vibrators have been used widely for preventing the senility of the elderly, for curing or preventing melancholia, for rehabilitation during convalescence, and for other similar purposes.